Grinding-machine.



PATENTED' JUNE 14, 1904.

G. 'HQ NORTON. GRINDINGMAGHINE.

YPLIUATION HLnp rma. 1, 1901.

9 SHEETS-SHEET 1.

.N0 MODEL.

PATENTED JUNE 14, 1904.

C. H. NORTON.

GRINDING MACHINE.

APPLIoATIoN FILED PEB. 1, 1901.

9 SHEETS-SHEET 2.

N0 MODEL.

6.5mm@ (har/e5 Norton,

L www PATBNTBD TUNE 14, 1904.

No MODEL.

s SHEETS-SHEET '3.

. mmm wl mmm \Nmm c lT/ead Charles H. Nori-0N.

W 'uf-346%' No. 762,838. PATENTED JUNE 14, 1904.

o. H. NomroN.y GRINDING MACHINE.

APPLICATION FILED FEB. l, 1901.

N0 MODEL. v 9 SHEETS-SHEET 4.

O O 1n I; ilIli llllnlllll lllvl llllll v y Charles HJYOrro.

N0 MODEL.

CLD

PATENTED JUNE 14, 1904. C. H. NORTON.

GRINDING MACHINE. APPLIOATION FILED P11111, 1901.

9 snnETs-snnm'- PATE NTED JUNE 14 G. H. NORTON.

GRINDING MACHINE.

APPLIUATION FILED FEB. 1, 1901.

9 SHEETS--SHE-ET 6.

N0 MODEL.

Ouv-@n Charles@ H Novon W. weg/ PATENTED JUNE 14, 1904.

C. H. NORTON. GRINDING MACHINE.

APPLIOATION FILED FEB, 1l 1901.

9 SHEETS-SHEET 7.

CL @11n/egV N0 MODEL.

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oo (D D000 N No: l.\ RN@ m O l 0o R l w N "QN m I m Q '3 @l m m f' /Yr 1B 'N 23 C\l N N m Ol @Muff G. H. NORTON.-

GRINDING MACHINE.

APPLIOATION FILED m13. 1, 1901.

PATENTED JUNE 14, 1904.

9 SHEETS-SHEET 8.

C. AH. NORTON.

.PATENTED JUNE 14, 1904 y GRINDING MACHINE.

v APLIoATIoN FILED PEB. 1, 1901.

N0 MODEL.

9 SHEETS-SHEET 9.

I? any. l I

` `lution of a hand-wheel.

no. masas.

UNITED I STATES Patented June 14,1904.

PATENT OFFICE.

CHARLES H. NORTON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTONGRINDING COMPANY` OF WORCESTER, MASSACHUSETTS, A

CORPORATION OF MASSACHUSETTS.

GRlNDlNG-NIAQHINE.

SPECIFICATION forming part of Letters Patent No. 762,838, dated June 14,1904.

' Application filed February l, 1901. Serial No. 45,65I. (No model.)

To rl/Z whom, t r11/wy concern:

Be it known that I, CHARLES H. NORTON, a citizen of the United States ofAmerica, and a resident of the city of Worcester, county of 5 Worcester,State of Massachusetts, have invented certain new 'and usefulImprovements in Grinding-Machines, of which the following is aspecification.

My invention relates to grinding-machines adapted, primarily, forgrinding straight, eylindricaL and taperA Work with minute'accuracy. Itembodies in its construction certain improved features by which areattained its chief objects-viz., great rigidity of parts, minuteaccuracy in grinding heavy work, simplicity and cheapness ofconstructiomsimplicity, ease, and convenience of operation, desirable`adjustments, changes of speed in its moving parts, and automaticoperation.

Still further desirable objects will be evident from the descriptionwhich follows.

Several of the chief features of my invention may be briefly referred toas follows:

One feature consists in inclining theeplane of the supporting-ways, alsoin the particular location of the supporting-ways on the table and inthe construction of the table to form a permanent water-guard. Amongotherr advantages this prevents any tendency to rock-y ing, givesrigidity, and insures accuracy. f A further feature'of my inventioncomprises the worm-andrack mechanism mounted in the swivel-table, lbymeans of which the latter' may be turned on its pivot by the revo- Thiscontributes to. ease and convenience of operation. L

Other important features of my invention are the speed-change means forthe Work,l speed-change means for the table, the arrange- 40` ment andapplication of the speed-change means for the work and speed-changemeans for the table independent of eachother. The speed c hange for theWork is accomplished by means of the swinging speed-cone hung fromthehead-stock and geared` to the headstock gear. The belt, in the loop ofwhich said cone hangs, runs over an overhead driting-drum and is easilyshifted from one pulley-section of said cone to its adjacent section. upor down conical sections between said 5L pulley-sections, and is-held inthe position to which it is 'adjusted by a slidable belt-guide.

Still .further features of my invention consist in mounting the hand andautomatic table-feed and automatic table-reversing mechanisms on asingle plate fastenedlto the front of the machine, also in theconstruction of the automatic reversing and feed mechanism, and,further, in the slidable engaging pin for overriding the table-reversingdogs, avoiding moving saiddogs when once set and preventing accident ifthe table is moved by hand beyond the limit of travel set by said dogs.

My invention further. comprises the variable-table-speed mechanismmounted on the 6 5' front of the machine and having the speedr cone withthe conical sections between the pulley sections, so that the belt maybe pushed from one pulley-section to its adjacent one, and the beltguide and shifter.

My`improvements in table-speed mechanism further include the backgearing in combination with said speed-cone and the swingingidler-pulleys, under which the belt runs to the speed-cone and whichkeeps it taut as it comes from an overhead drum.

Other features of my invention consist in the wheel-carriage-feedmechanism whereby the wheel-carriage is movedI directly by the screwrunning in a bath of oil, which is en- 30 gaged by the long half-nutfast to the carriage, also in the means for supporting said screwbeneath said nut. By. these means the screw is rigidly supported and isconstantly well lubricated, both of which are essential to accuracy inoperating. e n

,The hand, automatimand micrometer crossfeed mechanisms'by which thefeed-screw is operated are other important features of my improvement.simple and substantial mechanism. The hand cross-feed mechanismcomprises an operatingwheel revoluble on a fixed pin and connected,through the micrometer mechanism, with a train of gears operating thefeed-screw. The 95 micrometer cross-feed mechanism 'consists in Thesefeatures consist in veryn Vparticular means whereby saidmicrometerpinion is held in fixed relation to said train of gears orloosened, as desired, comprises a permanent connection with thehand-wheel and means for making the latter fast or loose on the shaft,as desired, for micrometer or hand feed, respectively.

Other features intended to be covered by this application are the meansby which the micrometer-pinion is mounted to be withdrawn fromconnection with said gear or train of gears, the index having holesandthe slidable index-pin connected with the pinion and adapted to lit saidholes, which in this case are located one eighth of a circumferenceapart and measure from hole to hole a carriage movement of one-eighth ofone-thousandth of an inch.

The automatic cross feed is another improvement which consists in areciprocating pawl operating between the teeth of a gear connected withthe cross-feed to revolve said gear one or more teeth at a time. Saidpawl is re- Iciprocated by pitman connection with a pinion oscillated bya rack connected adjustably to the table-reversing mechanism, wherebythe automatic cross-feed is operated as the table is yreversed at theend of each run. V-A particular feature of this part of my invention isthe means for providing a fixed limit of' movement of said pawl inonedirection and a variable limit regulated by adjustment of saidmechanism in the other direction.

There are several other features of my invention besides the chief onesabove pointed out, which are described below and which I desire andintend to cover in this application and concerning which I havereference to the following description and the drawings filed herewith.l

Figure 1 is a side elevation of the machine. Fig. 2 is an end elevationwith the tail-stock left off. Fig. 3 is a view, partly in elevation andpartly in section, the section through the base of the machine and thewheel-carriagefeed mechanism being taken on the axis of the feed-screw.Figs. 4 and 5 are top and end views, respectively, of the .head-stock.Figs. 6 and 7 are sectional view and elevation), respectively, of thehand and automatic tablefeed mechanism. Figs. 8 and 9 are elevation andsectional view, respectively, ofthe variable-speed mechanism of thetable-feed. Fig. v

10 is a detail view of the operating-handle for throwing in the backgears in said speed mechanism. Fig. 11 is an elevation of theautomaticwheel-carriage feed and micrometerfeed. Fig. 12 is ase'ctional viewthrough the micrometer and hand feed. Fig. 13 is a seo-l tionalviewshowi ng the mechanism for swingi ing the table on vits swivel.

Fig. 14 is'a sectional view through the' wheel-carriage i and itsfeed-screw. of the table-shifting dogs, and Fig. 15 is a top elevationof the machine.

The general form in plan'view of the base A of the machine is that ofthe letter T. Said base is provided at its three extremities withsupporting-legs a a a, on which the machine rests, thus providing athree-point or tripod support, which avoids rocking on an unevenfoundation and is solid and steady. Integral with the base and locatedadjacent to that portion of the same over which the wheel-carriage issupported is the water-tank F. Its location is such that it directlycatches the wa- Fig. 16 is a side view of one ter which is deliveredupon and falls from the' work, grinding-wheel, platen, and swivel-table,thus avoiding the use of return pipes and channels, which are liable tobecome clogged. The tank is provid ed with the perforated cover,

through which the rotary pump H is mounted, which is run from anoverhead countershaft. (Not shown.) The base A is hollow and interiorlybraced with integral webs or trusses, (not shown,) as is usual in largebasecastings. The portion a of the base which corresponds to thehorizontal portion of the T is provided on its Vtop with longitudinalhorizontal slideways 15 16, the bearing-surface of the way 15 beingangular and that of the way 16 fiat. Slidably. mounted longitudinally onand guided by the said ways is the sliding Hat-top bed or platen B,having slides 17 -18 adapted to fit said ways. 'The platen is operatedalong the base to carry the work across the face of the grinding-wheelby mechanism described below. The swivel-table C, having aflat baseresting on the flat horizontal surface 2O of the platen, is swiveledthereto near its middle point on the swivel pin or pivot 21. 'The endsof said swivel-table are proder transverse ways 241 25, respectively,provided on the sliding bed near the ends thereof. This swivel-tablecarries the head-stock D and the tail-stock E, having the centers d e,on which the work is mounted. Said table C can be swung around the pivotor-swivel 'pin on the platen B to place the axis of the work parallelwith or at an angle to the direction of movement of thev platen on itsways, thus providing for parallel and taper grinding. The means forswinging said `table on the swivel-pin is described as follows, Fig. 13:The table, near one end thereof, is provided with the transversechanrielor groove321 on its under .ide. worm-rac 322, which is pivotedon the pivot 320 in said platen. J ournaled' to the plate 323, which isfirmly fastened to the table, and extending downward into the interiorof said table is the worm-shaft 324, having the wormwheel 325 meshingwith said worm-rack and on the other end the hand-wheel 326. Thus itwill be seen that the table can bc swung on IOO ' vided with theintegral slides 22 23, fitting un- Fitting in said groove isthe of theaxis of the work and grinding-wheel.

its pivot by means of the worm working in said rack. In transversesection the swiveltable C is made solid-and substantially triangular inform, providing in itself a permanent .water-guard on its face 26 infront .of the ginding-wheel. formiug'one side of the triangular section,is

The base 19 of said table,

made broad and extends under the work,where it formsan apex withthesecondslanting side 26, whichserves as the permanent waterguard. Saidslanting side rises on an angle with said base to a p oint approachingthe lline The third side 27 is substantially vertical from the top ofsaid slanting side to said base. Thus a solid table andl support for thehead and tail stocks and steady or bearing blocks which may be attachedthereto is provided, making a solid and substantial support, which is'necessary in accurate grinding.

The direct work-support or holding devicesfviz., the head-stock'D andtail-stock E.- are carried by the triangular swivel-table on thesupporting-ways 2 8 29. The `plane of these supporting-ways is inclinedto the horizontal in front of and beneath the 'grindingplied to theother horizontal Ways for the sameppurpose, and my invention covers suchapplication.

My invention is not conned to a reciprocating platen or table, as saidtable might be made stationary andthe wheel-support reciprocatedwithoutdeparting from the spirit or scope of my invention. f

The way 28 is formed, as a fiat slideway isv located, near the base ofthe swivel-table sub stantially beneath the work.. The way 29 is Y madeangular incrbSs-segtion and located at lss the upper part of thetable'behind'the waterguard extension 30, forming a part of the tableitself.

The widely-separated supports for head and 26 of the table provides anaturaLwater-guard. This side is preferably-made concave between the way28 and the guardextension 30 and is provided about midway with thelongitudinal groove 31, having'a shoulder to receive theclamping-holtsof the head and tail stocks for securing the same inposition upon" the supporting-ways. This clamping' meanslo- -catedbetween the separated supporting-ways will allow the clamping-pressureto vary with- While this is shown as applied to the to revolve the same.This extension 30 protects the supporting-way 29 from water usedon thewheel.

out aecting the accurate alinement of the centers.

It is obviously desirable that the slideways I and bearings of themachine should be pro- To effect such" tected from water and dirt.protection, there is provided by the table and its extension 30,protecting the supportingway 29, the Water-guard 32, extending Well overthe supporting-way 28. The guard 33 extends over the slideway 16, andthe guard 34 extends into the recess 35 over the slideway 15. Saidguards 33 and 34 are attached to and extend longitudinally along thebase. Extending over the guard' 33 and attached to the platen B-for thelength of the same is the guard -36. The se overlappingguards andportions'of the platen and table effectively protect the ways. The bases38 39 of the headstock and tail-stock, respectively, are similar in formand conform, substantially, to the shape of the slanting front orconcave side of` the swivel-table. The upper parts 40 41 of said basesextend over the water-guard extension atthe top `of the swivel-table anddownward, where they are provided with the angular slides 42 43, adaptedto lit and travel on the supporting-way 29. The lower portions of saidbases are extended over the lower waterguard 32 and back under the same,where they are provided with theslides 44 45, adapted to be supportedand to travel on the supportingway 28. The head-stock and tail-stockclamping-bolts, (shown onl Fig. 3 on tail-stock only,)

as 46, having similar heads, as 48, fitting into,

the groove 31, are provided at the top within easy reach of the operatorwith the handlenuts 4950, which serve to draw the-bolt-heads fastagainst the shoulder of the groove 31, thus holding said stocks inposition. The i tailsto'ck is provided with the tail-spindle bearing 51,having the usual sliding spindle 52, screw, (not shown,) center e, andoperating-wheel 54, and in other respects having the wellknownconstruction. The head-stock is pro vided with a driving gear-wheel 58,mounted on a horizontal stud having the center d and suitable means (notshown) for lengaging a clamp or' dog, which is fastened to the work Aspeed-cone 60 is j ournaled inthe bearings 61 62, said bearings'beingmounted on arms 63 64, journaled suitably to the head-stock, the arm 63having the bearing 61 preferably journaled on an extension of thespindle and the arm 64 having the bearing 62 preferably journaled on a-portionof the head-stock; Said cone is provided with the small`gearfwheel 65, meshing with the gear-wheel 58. In this case said cone isprovided with eight steps or pulleys for the driving-belt 56 and haslocated between each step or pulley and integral therewith conicalsections 66 6 6v in order that the belt may ride up slideway 67 issuitably rigidly-mounted from the carriage is fed along the overheaddrum.

designed to be such that the belt runs freely in the belt-guide 68whatever portion of the cone the belt maybe guided -td and runningzon. i

The belt-'shifter comprises the slidable block 69, having the belt-guide68 mounted on one side thereof and provided with a gib-71, operating inthe longitudinal groove 73 on said \\slide. It is also provided with ahandle 74 for operating the same andA the spring-operated holding-pin75, fitting into holes on top of said slideto hold' the saidbelt-shifterrin its successive positions, said pin being adapted to bedrawn from the holes by the handle 76, connected therewith. A long drum55 of a length equal to the longest run of the carriage is mounted on acounter-shaft over the head-stock speed-cone just described. Thedriving-belt 56 encircles said drum and cone and is of such a lengththat the head-stock speed-cone rests in .its loop as in a sling, itsweight being suchl as to cause su iicient friction between said cone andbelt to drive the head-stock spindle.. Thus as the belt is shifted fromstep to step it is kept taut by the weight of .the one, and as belttravels on the By -raising the cone out of operative contact with thebelt the rotation A of the work may be stopped without stopping thetable-.feed or any other operation'of the machine or overhead work.

By the means above described all changes of speed throughout the wholerange of speeds are effected at the machine and not dependent onoverhead cones or o'n the speed of the workdriving shaft. The speed ofthe work-driving belt will be the Same whether the work is running onthe highspeed or the low speed. Moreover, the speed of the overhead drum'will be the same for any work speed, and this is that with the fastesttable travel the belt rides along it easily. Thus the speed of the workis entirely independent of the speed of the table.

suitably fastened thereto.

, of a'reversing-lever to be engaged by'dogs The table driveor feedmechanism by which the table is fed forward and backward, carrying thework across the face of the grindingwheel, is described as follows:Referring to Figs. 3 and 6, the flat sliding table or platen is providednear the middle of its under side with the longitudinally-extending rack478, The table-feed or platen-driving mechanism is mounted on the plate79. -The front of the base of the machine is provided with an opening80, through which said driving mechanism extends from the front of themachine. This mechanism yconsists of a train of gears connected with aplaten-drive-shaft and also of mechanism' for disconnecting the same andusing hand-feed.'

The automatic reversing mechanism for automatically reversing theplaten-feed lconsists on the platen clutch mechanism on said driveshaftand intermediate spring shifting mech- -operate the same.

anisrn. One feature of my invention consists in arranging and assemblingthe platen-driv- I in'g mechanism and automatic reversing mechaiiism onone plate mounted on the front of the base of tlie'm'ac'hine, thussimplifying the construction, saving -miieh expenditure df time andlabor and-consequent expense in manufacture, and assembling the partswher'e they are easily accessible. Referring again to Figs. 6 and 7,said platen-driving mechanism is mounted on the supporting-plate 75,which fits on over the opening 8O and holds said mechanism in place.Integral with said plate is formed the journal-bearing 81, the shaft 82of which carries fast on its inner end beneath the sliding table thepinion 83, which meshes into the rack 78. This shaft is provided withthe gear-wheel 84, also mounted fast thereon, which meshes with thegearing of the automatic table-driving mechanism.

On -the outer end of the shaft V82 a gearwheel 86 is keyed, into whichthe pinion 87 meshes. Said pinion 87 is revolubly mounted on the bearing88, fixed in the arm 89, which is held to plate 79 by the bolts 90. Saidpinion 87 is formed with a sleeve 91, onwhich is mounted fast theretothe hand-wheel'92, by means of which the sliding table can ber drivenback and forth when the automatic feed is disengaged. Said gears 86 and87 are covered and protected by the gear-cover 93, fastened tothe plateat 94 94. Said plate 79 is provided with a journal-bearing 95 below thesaid bearing 81, having the shaft 96. The small gear 97 is revolublymounted on said shaft and is provided 'on'A its face with the clutchmember 98, fitting a similar clutch member 99 on the collar 100, whichis keyed to said shaft, but capable of longitudinal movement thereon.Said collarI is furnished with the annular groove 101, into which thebifurcated shifting dog 102 engages. Said shifting dog is mounted on theshaft 103, slidable vin the bearing 104, which is integral with theplate. Said shaft extends outside said plate and is engaged by the lever106, fulcrumed on said-plate at 107 and having a handle to IlO Thus theclutch-collar 100 can be thrownl in of out of engagement with the clutchmember 99 on the gear 97, making said gear fast or loose, respectively,on the shaft, as desired. Mounted fast on said shaft 96 beside thecollar 100 is the gear-wheel 110,

by which said shaft is driven. Journaled Vin the bearings 111,formedintegral with said plate, is the shaft 112, on` the inner end ofwhich is mounted fast thereto the gear-wheel or pin-ion 113. On theouter end of said shaft `is keyed the bevel-gear- 114, cup-shaped in`order that the hub 'and shaft-nut may not be in position which wouldinterfere with the reversing mechanism. Said gear is set into a acup-shaped depression in the plate l7 9, so that the gear-teeth 116 maybe located near the face of'said plate.

' ing with thesame, but is capable of longitutally over the center ofthe gear 114. Said shaft is vprovided over the center of the gear withthe enlarged portion or barrel 120, which provides the annular shoulders121 122. The clutch-collar 123 is keyed to said shaft, revolvdinalmovement thereon. Said collar is provided with the toothed clutchmembers 124 125 andthe annular groove 126 into which the bifurcated arm127 of the shifting mechanism extends. Journaled on said shaft andfitting between the respective shoulders 121 122 and "the respectivejournal-bearings 118 119 are bevel-gears 127`` 128, engagingwith thegear 114 on opposite sides of its center. Said (gears are provided,respectively, with the integral toothed clutch members 129 130,extending over the edge of the barrel. drive-shaft revolves in onedirection only, and the clutch-collar is adapted to alternately engage,respectively, with the gears 127 128 to revolve the gear 114 in onedirection or the other, respectively. The clutch -collar is adapted tobeshifted by themovement of the platen and reversing-lever 131. In casesaid /clutch-collar was attached directly to said reversing-lever themomentum of the platen would not be sufficientafter one pairfof clutchmembers was disengaged to move the collar to ,engage` the other pair ofclutch members to reverse the platen.' To effect this reversal', aspring-actuated shifting mechanism "is l0- cated between saidreversing-lever andthe clutch-collar, which locks -thecollar alternatelyagainst movement in each direction,vv

respectively, thencompresses a spring to actuate the collar againstitsfrespective-lockingcatch when the spring operates to throw saidclutch-collar, effecting a reversal of the movement of the platen. Thismeans for automaticall;T shifting said clutch-collar and changing thedirection of the table-feed comprises the following detail mechanismattached to the plate 7 9: A slidable rod or plunger 133 is horizontallymountedover the drive-shaft 117 to slide in the bearings 134 Thebifurcated arm 127', engaging the annular groove 126 in theclutch-collar,is mounted fast on the slidable shaft 133 by means of theclutch or bridge connection'138, integral with the hubs 139139', whichare mounted fast to said shaft. These hubs are respectively providedwith the hardened catch-lugs 14() 141, adapted to be engaged by thelocking-catches 142 143, having the engaging shoulders 144l 145,respectively, and hinged, respectively, to the slide-bearings 134 135.These catches are also provided with the cani-faces 148 149,respectively, to be engaged by the cam-shoes 150 151 on thereversing-lever 131. Aspring The 135 on said' plate.

compression-collar 152 is slidably mounted on said rod 133. Between saidcollar and the hub 139l and around the rod 133 is mounted a spiralcompression-,spring 155'. On the other side o f said collar between thesame and the hub 139 is mounted the similar compressionspring 158. Saidsprings act against each other and hold the collar in its -intermediateposition on the rod. By these means when the clutch-collar is throwninto engagement with one clutch member-as, for instance, 129-thelocking-catch corresponding with that position of the clutch-collarengages behind the engaging shoulder, as 144, so that the said collarcannot be shifted until the catch, vas 142, is tripped by the cam-shoe151.

A similar operation takes place in relation to engagement with the thecatch 143.

Below the cam-shoes 150 151 the bifurcated a'rm 160 extends from thelever into engagement with the annular groove in the collar 152. As saidbifurcated arm of said lever clutch member 130 and moves the collar inone direction or the other the spring against which the latteris movedis compressed between it and its respective hub, -said hub, and itsconnected elements, the bridge and bifurcated arm, engaging the slidingclutch-collar being held against the action of said spring by thelocking-catch engaging the locking-shoulder on said hub. When the springhas been compressed a certain distance, the tripping cam-shoe comes intoengagement withthe cam-face of the locking-catch and releases it. Thespring whichhas been compressed then acts to throw the rod and itsconnected mechanism with said clutch-collar, which is thus positivelyand instantaneously shifted, reversing the direction of the platen ortable feed. Said reversing-lever is thrown at either end'of the tablerun. by being brought into engagement at its upper end with thereversing blocks or dogs 161 162, fastened to the platen in the groove154, along. which they may be adjusted and held by suitable :i oo

lIQ

clamping mechanism to regulate the length of the table run. The upperend 163 of the reversing-iever is provided with the slotted slideway164. The slidable block 165, having the engaging pin 166 extendingthrough and into the path of the reversing-dogs, is suit- .ably held toslide l'in the slotted way. Said reversing-dogs are lprovided with theengaging faces 167 168 to 'engage said pin. The

engagement of these faces with the pin shifts the lever, compresses thespring on the side that is locked, trips the lock, and shifts theclutch-collar. If, however, it is 'desired to move the -table back andforth by hand without limiting its movement to the distance between thedogs, the engaging pin 166 in the sliding block will come into contactwith the v cam-face of either dog, and if moved farther than required tocompress the spr1ng, unlock the catch, and accomplish the shlftmg thepin-block will slide ip the slotted way and ride over said dogs. Thesaid dogs are provided with the faces 169 170 on the outside, so thatthe pin and slidable block may ride over them from the outside withoutaffecting the shifting mechanism in any respect. Thus I attain theobvious advantage of being able to move the carriage afterthe dogs areset without changing Atheir position or manipulating the sliding pin onthe reversing-lever and which normally stands in the path of said dogs.It will be seen that the reversing mechanism is liable to no unduestrain owing to the movement of the carriage, and if any possibility themachine Should be started when the engaging pin is outside the spacebetween the blocks afterhaving overridden one of them the shiftingmechanism will have been so set by its operation immediately precedingits overriding that the automatic feed willbring the table back wherethe pin will again be between the blocks. Thus possibility of accidentfrom a wronglyset table feed is reduced to the minimum. The table-feedand reversing mechanism above described is covered by the cast-ironcasing 171, Fig. 1, protecting itfrom dust and dirt. Said table-feedmechanism is driven through the shaft 117 by means of the variable-speedmechanism described as follows: the shaft 117 is journaled in thebearing 172 on the frame 173. Said frame is constructed to be fastenedto the front of the'base of the. machine around an opening into whichthe speed-cone extends laterally. The shaft ends at 175. Directly on aline with said bearing and journaled in the frame at 176 and 177 is thespeed-cone shaft 178, on which the hollow speed-cone 179 is rigidlymounted. Said cone is provided with eight steps or pulley-sections 180180, 6to., between which are the conical sections 181 181, &c., up anddown which the belt may be easily shifted. Over the said cone abeltshifter slideway 182 is provided and suitably fastened at each endto the frame 176 and having the longitudinal groove 183. On this Way isslidably mounted the shifting block 184, havingvthe Agib 185; operatingin the longitudinal groove 183 inwsaid slideway. Fastened to the frontof said block and extending back within the base is the belt-guide 186,having the fork embracing the belt. Said shifting block is provided withoperating-handle 188 and an ordinary spring holding-catch 189, tittlnginto successive notches 190 in the coverplate 191. Said cover-plateextends over theY y said speed mechanism and protects the same from dirtand dust.

The belt 196, which runs to the speed-cone, is driven from acounter-shaft pulley or drum 187 and extends under idler-pulleysthroughthe opening at the back of the base and around said speed-cone, as shownin Fig. 2. The idler-pulleys 192 193 are mounted on the arm 194, whichis swung from the base at 195, and

'same for every speedof the table.

same on said speed-cone.

1t will be noted that the change of speed of the table is effectedentirely at the machine and is not dependent on overhead cones or on thechange of speed of the driving-shaft. The speed of the table-drivingbelt remains the Furthermore, when the speed of the work is changed thespeed of the table is not affected, and any of the table speeds can beused whatever the revolution of the work may be or any of thc workspeeds used without changing the re.- ciprocating or table speeds.

vThe speed-cone is 7connected to the platen drive shaft directly ybyclutch means or through `backgearing, which reduces the speed. The shaftis extended between the bearings 172 and 176 and carries the gearwheel197, revoluble thereon. This gear meshes wi th the gear-wheel 198,mounted fast on the Shaft 199, which is journaled in the frame 173. isrigidly mounted the gear-wheel 201, which in turn meshes withfthe gear202, fast to the shaft 178 of the speed-cone. The gear 197 is providedwith the clutch-teeth 203 on the inside face thereof, adapted to engagesimilar clutch-teeth on the clutch-collar 205,which is keyed on saidshaft and slidable thereon` A clutch member 206, having teeth 207, ismade fast to the shaftof the speed-cone, andv the clutch-collar 205 isprovided on its adjacent face with corresponding clutch-teeth to engagethe same. Said clutch-collar is provided with the annular groove 209,into which the bifurcated end of the clutch-lever 210 extends. Saidlever is fulcrumed at 211 to the frame and hasnthe conveniently-locatedoperating-handle 212. Thus by means of the mechanism just described theshaft 117 mayvr vbe thrown into rigid revoluble4 engagement with theshaft of the speed-cone, -it being d isengaged in such case from theback gearing, or said drive-shaft may be thrown into revolubleengagement with the back gearing, in which case the shafts aredisconnected.' Thus On the opposite end of said shaft IOO IIO

a rapid table speed can be had when roughing to remove stock rapidly;For finishing with the same grinding-wheel without stopping the work ortable the lever'212 is shifted, which throws in the back gearing, thusinstantly reducing the table speed suitable for the finishing cut.

The grinding-wheel carriage G is mounted on the wheel-slide orslideway-base 215, fastened to the top of the base A on that partcorresponding to the vertical portion of the T, and is provided formovement on said base 1215 at right angles to the movement of thesliding table with the fiat and angular slides 216 217, respectively.Said slides fit corresponding integral slideways 218 219 in the top ofthe base215. Th'egrinding-wheel 220 a nozzle 23() directly on the workatthe point is mounted on a spindle, which has the journal-bearings 222223 integral with the carrlagc. the spindle between said bearings. Awheelguard 225 is permanently attached to the. car. riagc and isprovided with the removable sidey 226, held in place by the catch 227.The iron water-pipe 228 is mounted. above .the wheel by means of the arm229, attached to the wheel-guard. lt delivers water through of contactwith the grinding-wheel and is provided with the valve 231 to regulatethe flow. A iiexible hose-pipe 232 is attached to the iron water-pipeand runs to the pump, which may be of any well-known construction,though preferably of the rotary-fan style. Said pump is driven in anysuitable way and is placed in the tank, which is integral with the baseand located beneath and at the side of the grinding-wheel.

The wheel-carriage feed-screw rod 233 is journaled to the base parallelwith the slideways of said carriage by means of the bearing 234 atbackof the machine and beneath the carriage and the bearing `235,fastened to the inside and front of the base, and is provided at the.back end with the shoulder 238, which may take the end thrust againstthe bearing 234,.and at its front end with the shoulder 239, to whichthe bearing 235 may be adjusted to take end thrust in'uthe oppositedirection.

Besides the supports for the screw-rod provided 'by thejournal-bearings/just described the enlarged threaded portion 24()thereof is supported by the cradle-bearing 241. Said cradle-bearing isprovided with the circular peripheral bearing trough or cradle 242, inwhich the screw, the thread of which is cut square, rests and revolves.Said bearing 241 is supported by attachment and 244. In order to provideproper lubricationfor this bearing, an oil-trough V245 is providedbeneath the bearing and integral therewith. It is closed at the sidesand open at the ends 248 249. The oil stands in this trough at`a levelhigher than thelowest point in the peripherywof the feed-screw. Then thescrew is revolved, the oilis fed along by the threads on the principleof the well-known Archimedes pump, keeping up a circulation of oil onthe bearing in one direction and in the trough beneath the bearing inthe opposite direction.

rlhe screw is threaded to the wheel-carriage by means of the long halfnut or block 250, bolted thereto. Said block is made eircularly concaveto fit the screw and'is provided with similar threads to operativelyengage with saidscrew. i

The feed-screw mechanism providing hand, automatic, and micrometer crossfeed` by which the wheel-carriage, and thus the wheel, is moved withminute accuracy and positiveness, is described as follows: AThegear-wheel A driving-belt pulley 224 is fixed to to the base at 243 f251 is iixed on the end of the .screw-shaft A233.

Extending from the journal-bearing 235 is the arm 252, in which is fixedthe bearing pin or spindle 253, comprising the cylindrical bearing 254,the reduced cylindrical bearing 255, and the screw-threaded end 256. Asmall gear 257, having the teeth meshing with the teeth of the gear 251,is mounted on ,the cylindrical bearing 254. Said gear'has the extendedhub l forming the hub of a large gear 259. vA fixed/- washer 260 issuitably mounted fast on the reduced cylindrical bearing 255 of saidspindle, adjacent to the shoulder 261, formed between the bearingportions'254 and 255. Adjacent to said fixed washer is the loose leatherfriction-washer 262, an/d adjacentA to the latter is the hubof thehand-wheel 263, which is revolubly mounted on said reduced portion ot'said spindle, and the washer 264, suitably mounted to slide but not torevolve on said spindle. The knurled set-nut 265 Vis threaded on the end256 ofthe spindle and is adapted to -have itsannular shoulder 266screwed up against the washer 264, pressing the hubof the ,wheel 263between it and the lixed washer 260 and friction-washer262, lholding thesame fast to the shaft,which is rigid with relation to the base. Whensaid nut is loosened, said handwheel may be revolved on the shaft.

The index mechanism is mounted on the arm 267, rigidly fixed by means ofthe screws 268 to the hand-wheel 263. Said mechanism is balanced by theoppositely-extending weighted arm 269'. Said arm is provided with thefbearing 27 0in which the revoluble barrel 271 is journaled.y Withinthis barrel is located shank IOO 277 of the slidable pinion 272, theteeth of which mesh with the teeth of the gear 259.

'Said pinion is held from revolving in said barrel by a pin 273, fixedin the enlarged hub 274 of the pinion 272 and slidable in a longitudinalslot on the inside periphery of the barrel. Extending from said hubthrough said barrel and having a slidable bearing 276 through the end ofthe sleeve is the shank 27 7, having a knurled IIO handle or thumb-piece27 8,l by which the pinion 27 2 maybe withdrawn from engagement with thegear 259 and placed in any circumferential position around said gear,preferably at the top, for the convenience of operating and for throwingout the automatic feed ,as de scribed below. A spring 280 normally holdssaid pinion in engagement with the gear 259. Said barrel is provided onone end with the shoulder 279,y which bears against the face of thebearing 270, and at the other end carries the split collar 281, madefast to said barrel against bearing 270. Said collar is .provided withthe extending arm 282, having the integral hollow casing 283, carryingthe slidable indexpin 284. Said index-pin is provided with the bearing285, fitting the interior of the casing 283, and the smaller integralpin-rod 286, slidable through the end of said casing and having thehandle or thumb-piece4 287. A

' and shield fast shoulder 289 compression-spring 288 is located betweenthe of the pin-rod and the inside end of the casing and acts to forcethe index-pin 284 into the holes of the index 290. The indeX 290 isintegral with the arm 267, the holes 292 being located in a circlearound the axis of the pinion. Said holes in the particular devicedescribed are eight ih number, and the movement of the index-pin fromone hole to another makes a wheel-carriage movement of one-eighth ofone-thousandth of an inch. i

gear-.cover 293 for thegear 257 is provided to protect said and alsofurnishes a bearing for a portion of the automatic feed mechanism,described as follows: A pinion 295 is r'evolubly mounted suitably tosaid gear-case and is provided with the flange 296, between which andthe gearcase the rack 297, engaging said pinion, slides. Theconnecting-rod 298 is journaled, by means of crank-pin 298, to theoutside of said flange and is .Journaled at the other end to thecrosshead 299, which is slidably mounted in the shdeways 300 on saidgear-case. The pawl 301, having the tooth 302 for engaging the teeth ofthe gear, is journaled to said crosshead. Said pawl is provided with theextension 304, which is adapted to engage the shield 305. Said shield isfastened to the arm 267 and extends over a series of the teeth of thegear 257 toward said pawl. As the pawl 301 1s reciprocated and the gearhaving the arm y thereto is fed thereby the shield gradually nears saidpawl and finally comes into contact with the same, throwing and holdingit out of engagement with the gear-teeth. Thus the automatic feedmechanism can be set to be stopped at a certain predetermined point, asthe index-pin can be moved to any hole, moving the shield and uncoveringmore or less teeth of the gear 259. The rack is provided with the arm305, em-

:bracing the pinion on its under side, thus holdmg the rack inengagement with the pinion. The end of the rack is journaled to theadjustable block 306, which may be set at any position on the curvedslide 307. The curved slide 307 is fastened at 308 to the reversinglever131 and is moved thereby when the shifting lever is moved. As theshifting lever is moved the rack-revolves-the pinion and the crank-pin298 is carried from one side of and above its lowest position to theother side of and above said position, the distance said crankpintravels depending on the adjustment of the block 306 on the arm 307.Thus it will be seen that the pawl 301 is always fixed as to its lowerlimit of movement.

The operation of the hand -feed for the wheel-carriage is as follows:The nut 265 is loosened, permitting the hand-wheel 263 and its connectedarm 266 to revolve on the shaft 255. Said arm 266 is fast to the gear259 by means of thepinion 272, which does not revolve when the index-pinis set in one of the gear from dust and dirt index-holes. Thus by therevolution of the hand-wheel the gear 259, which carries the pinion 257,meshing with the gear 251 on the feed-screw, is revolved and thewheel-carri age moved. The micrometer feed is connected bytightening thenut 265, making the wheel 263 fast on the shaft 255. Thus the bearing ofthe barrell 271 has a fixed position, and when the indeX-'pi-n is drawnout and moved from hole to hole the pinion 272 revolves the gear 259 itsmeasured distance and in turn the feed-screw 233. I have described themechanism which I claim as my invention as applied toa grinding-machine;but it is obvious that it may he applied to other machines.withoutdeparting from its spirit and scope. I have, furthermore, not attemptedto describe the changes and modifications which may be made withoutdeparting from the invention. For example, it will be clear that severalfeatures of my invention may be applied to that type of grinding-machinein which the wheel is reciprocated and the work held stationary. Suchadaptations are, however, within the scope of my invention and areintended to be protected herein; but

- What I' claim, and desire to secure by Letters Patent, is-

1. In a grinding-machine the combination with a suitably-mountedgrinding-wheel, of suitable work-holding means and separated horizontalways for said work-holding means, the plane of said ways being inclinedfrom a point opposite the wheel downward to a point beneath the work.

IOC

2. In a grinding-machine the combination with a grinding-wheel,work-holding means, means for moving the work and wheel together,separated horizontal ways for said Work-holding means, the plane of saidways being inclined to the plane on which the work and wheel aremovedtogether.

3.v In a grinding-machine the combination with a wheel-slide,agrinding-wheel mounted thereon, work-supporting devices, and horizontalways for said devices, the plane .of said ways beinginclined to theplane of said wheelslide.

4. In a grinding-machine the combination with a suitably-mountedgrinding-wheel, of a work-supporting table, having an inclined frontforming a permanent water-guard and provided with horizontal ways,theplane of which is inclined in front of said wheel, and work-holdingmeans mounted on said ways.

5. In a grinding-machine the combination with a suitably-mountedgrinding-wheel, of a work-supporting table, having an inclined faceforming a permanent water-guard and head and tail stocks mounted onseparated ways located on opposite sides of said face.

6. In a grinding-machine the combination with a suitably-mountedgrinding-wheel, of a work-supporting table, having an inclined IOS .plane of said Ways being inclined to the horizontal and approaching thenormal to theline of pressure between the work and wheel.

8. In a grinding-machine the combination with a suitably-mountedgrinding-wheel of a work-supporting table having widely -separatedinclined ways, head and tail stocks adapted to slide on said ways andclamping' means for said head and tail stocks located between said ways;y

9. In a grinding-machine the combination with a suitably-mountedgrinding-wheel, of a work-supporting table of substantially triangularcross-section and having an inclined front forming a permanentwater-guard, of head and tail stocks mounted on said table, andhorizontal Ways for said head andtail stocks, one of which is mountedsubstantially beneath the 'wol-k.

10. In a grinding-machine the combination with a base, of a tablesuitably mounted over said base, head and tail stocks which aresupported by said table, two supporting-ways on said table forsupportingsaid head and tail stocks, one of said ways being located substantiallyat the base of said table and the other of said ways being located abovesaid base oit' said table and separated at a distance from saidfirst-mentioned way.

11. In a grinding-machine, the combination with a base, of a tablesuitably mounted over said base, head and tail stocks which are sup`-ported by said table, two ysupporting-ways on said table forsupporting'said head and tail stocks, one of said ways being locatedsubstantially at the base of said table and substantially under thework, the other of said ways being located l'above said base of saidtable andseparated therefrom by a side of said table, and clamping meansfor said head and tail stocks respectively located between said ways.

12. In a grinding-machine, the combination with a base, of a tablesupported over said base, said table being of substantially triangularform and having its base, at the apex formed with the same and aslanting side, extending substantially under the axis of the work, andhaving a slanting side extending toward a level with the axis of thework and forming a permanent water-guard2 said table having twosupporting-ways, one located on said slanting side near the base of saidta- `ble and the other located on the back side near the top thereof,and head and tail stocks supported' on said Ways, substantially asdescribed. 13. Agrinding-machine comprising abase,

a table, a grinding-wheel arranged at one side thereof, means forreciprocating said table, head and tail stocks which are supported bysaid table, means for rotating the work about an axis between said headand tail stocks, two guideways o'n said table for supporting saidstocks, one of said ways consisting of'a plane surface which is locatedat the side of the ta-` ble next the wheel, substantially under saidaxis, and the other way consisting ot' two. surfaces arranged at anangle and located on the opposite side of the table above the way firstnamed.

14. A grinding-machine comprising a base,

a table, a grinding-wheel which is arranged at one side of said table,means for reciprocating said table, head and tail stocks, means forrotating the work about a fixed axis therebetween, two guideways on saidtable for supporting said stocks, one of said ways beinglocatedat theside of table nearest the wheel and substantially under said'axis, andthe other way beingV located on the opposite side of said table, abovethe way first namedl and at the opposite side of the work from thewheel. g f

15. The combination with a table having a slanting side forming apermanent waterguard, of work-supporting means located at opposite sidesof said slanting side, of agroove *in said slanting side between saidWays, and

a clamping-bolt engaging said groove.

16. The combination with a base, of a platen which is adapted to slidethereon, a table which is supported on said platen, a swivel connectionbetween said platen and table, a Wormrack swiveled to said platen andslidable in a groove in said table, a Worm-gear journaled in 'said tableand engaging said rack `vand an operating-handle for said worm-gear,substantially as described. I

17. In a grinding-machine, the combination with a base, of substantiallyT-shaped form in plan section, a platen mounted on theportion of saidbase corresponding to the horizontal portion of the T, work-supportingdevices mounted on said platen, a grinding-wheel journaled and supportedover the portion of said base corresponding to the vertical por- IIOtion of the T, and movable along said vertical ,l portion to and fromsaid horizontal portion,

a water-tank located in the angular space at:

ranged vto prevent water from iiowingg/over the bearing-surfaces and todischarge said Water directly into said tank, substantially asdescribed.

18. A grinding-machine comprising abase,

la grinding-wheel, a water-tank located at the rear side thereof,y atable which is supported by said base which is shaped similarly to awater on said wheel, and water-guards coperating with the inclined sideof said table for returning the water directly to the tank without theemployment of gutters in said table;

19. The combination with suitable worksu'pporting devices of a suitablymounted grinding-wheel, means for accomplishing a reciprocatory movementbetween the work and wheel, a driving pulley and belt for said means andvariable-speed mechanism adapted to vary the speed of said reciprocatorymovement inldependent of the speed of said pulley and 20. Thecombination with a table, of worksupporting devices carried thereby,asuitablymounted grinding-wheel, a driving pulley and belt for rotatingthe work and means whereby shifting the belt varies the speed of'rotating the work independently of the speed of said belt.

21. The combination with suitable worksupporting devices, of asuitably-mounted grinding-wheel, means for rotating the wheel, means forrotating the work, a speed-changing mechanism for varying the speed ofrotating said work, means for accomplishing a reciprocatory movementbetween the work and wheel, speed-changing mechanism for varying thespeed of said reciprocatory movement, each speed-changing means beingindependent of the other, whereby either can be changed through itsrespective range of speeds without changing the other.

22. The combination with a grinding-machine having suitable drivingmeans, of a grinding-wheel, work holding and rotating devices,reciprocating devices for accomplishing a reciprocatory movement betweenwork and wheel, of a speed-changing device for said work and aspeedTchanging-device for said reciprocatory movement, each ot' saidspeedchanging devices being located on the machine and independentof thedriving means, whereby v all changes of speed are effected at themachine independent of the driving means.

23. In a grinding-machine having a suitably-mounted grinding-wheel andwork-supporting devices, means for rotating the work, means foraccomplishing a reciprocatory movement between said work and wheel andmeans for stopping the rotation of the work independently of any otheroperation of the machine.

24:. In a grinding-machine having a suitably-mounted grinding-wheel andwork-supporting devices, means for rotating the work,

means for accomplishing a reciprocatory movement between said work andwheel and means for stopping the rotation of the work without stoppingsaid reciprocatory movement comprising a swinging cone resting by itsown weight in its driving-belt, whereby said cone can be raised and thework stopped. 25. A grinding-machine comprisinga table, agrinding-wheel, work-supporting devices which are carried thereby,driving means which rotate at a fixed speed, for rotating the work aboutits axis, intermediate belt-andcone' means for varying the speed ofrotation of the w'ork, means for reciprocating said table, andbelt-and-'cone means for varying the speed at which said table is movedindependently of the speed at which the work is rotated.

, 26. A' grinding-machine comprising a ta- Able, a grinding-wheel,work-supporting devices which are carried thereby, a plaindriving-pulley from which the reciprocating table is driven, a4cone-pulley for varying the speed of the reciprocating table, a beltbetween said plain pulley and cone-pulley, means for keeping said beltin operative engagement with said pulleys,'and means connected with saidpulleys for reciprocating said table and means for guiding and holdingsaid belt.

27. A grinding-machine comprising a table, a grinding-wheel,work-supporting devices which are carried thereby, a plain drivingpulley or 'drum from which the work is driven, a cone-pulley for varyingthe speed of the work, a belt, means for keeping said belt in operativeengagement withsaid pulleys, and means for guiding and holding said bet.v

28. The combination with a base, of a grinding-wheel, work-supportingdevices mounted, over said base, means for accomplishing a reciprocatorymovement between the work and wheel, means'for rotating the work aboutits axis comprising a driving-pulley, an endless belt, and stepped conehaving a surface of revolution of gradually-increasing diameter between`its steps, and means for keeping said belt taut in whatever position itmay be on said cone.

29. The combination with abase, ofa grinding-wheel, 4work-supportingdevices mounted over said base, means for reciprocating said work withrelation to said wheel, means for rotating the work about its axis atdifferent speeds comprising a driving-pulley of uniform diameter, anendless belt and stepped cone having substantially conical sectionsbetween itsv steps, said cone being swung in a loop of 'said belt, thelatter being held taut by the weight of said cone.

30. The combination with a base, of agrinding-wheel, work-supportingdevices mounted over said base, a rotating drum of substantially uniformdiameter, means driven from said drum, and speed-varyingmechanism corn-TOO IIO

ter, means driven from said drum for rotatn ing the work about its axis'at different speeds comprising a cone, pivoted arms connected with andextending laterally from one of said work-.supporting devices forsupporting said cone, a belt which passes around said drum land cone, anadjustable belt-guide, means for locking the same at each step of thecone, said parts being arranged so that said cone will be supported bythe belt inn various positions of the latter thereon, whereby the beltis held taut by the weight ofthe cor e.

32'. "1, `he combination with a base, of 'worksupporting devices mountedover said base, a belt, a rotating pulley or drum, a steppedspeed-conehaving conical sections between the `steps thereof for the belt to rideup and down when shifted, and a shifting and.guid-" ing mechanism forshifting and guiding said belt, substantially as described.

33. The combihation with a base, of worksupporting devices mounted oversaid base, a grinding-wheel suitably mounted on said base, means foraccomplishingv a reciprocatory movement between said wheel and work,

speed-change mechanism for said reciprocating' means comprising adriving drum or pulley, a cone, a belt from said pulley to said cone,means for taking up the slack" in said belt whatever the position of thesame on said cone, and means for shifting said belt to its variouspositions on said cone. v 34. The combination with a base, of areciprocating platen mounted on said base, means for reciprocating saidplaten on said base,and platen speed-change mechanism comprising adriving-pulley, a stepped speed-cone having conical sections betweensaid steps ,for

the belt to ride up and down when shifted, a

belt which passes around said pulley and said cone, an adjustablebeltguide, means for locking the same ateaclrstep of the cone, and idlermeans for taking up the slack of said belt.

35. A machine. of the class described comprising a base, a platen,work-supporting devices which are carried thereby, means for rotatingthe work about its axis comprising a drum and cone, and a driving-beltwhich passes over said cone, and means for taking up slack in said belt,means for moving said table with respect to said base, said meanscomprising a drum and cone, a driving-belt which passes thereover, andmeans for takin-g up. the slack in said belt in the various positions ofthe latter on said cone.

36. The combination with abase, of a grindwheel, a reciprocating table,a rotating driving-pulley for operating said table, a speedchangingmeans for varying the speed of reciprocating table comprising acone-pulley, a belt, anadjustable belt-guide, a clutch, speedchanginggears and gearing means connected with said table adapted to beconnected with saidspeed-changin'g means by said clutch.

37. A grinding-machine having a table for the Work in combination with agrindingwheel, means for advancing said wheel toward the work upon leachreciprocation of the table, comprising a ratchet-wheel, connectionsbetweenx said ratchetwheel and the grinding-- wheel support which areadapted to move I said grinding-wheel and work together when saidratchet-wheel is rotated, a suitablyguided reciprocating pawl, means forreciprocating said pawl whereby the limit of its travel in one directionis fixed, and means for Varying the amplitude of its reciprocation inthe'other direction, substantially asdescribed.

38. A grinding-machine having a supportfor the work in combination witha grinding- Wheel, means for advancing said wheel toward the work uponeach reciprocation between the work and wheel comprising aratchet-wheel,

connections between said ratchet-wheel and the grinding-wheel supportwhich are adapted to move said wheel and work together, asuitably-guided reciprocating pawl, acrankpin, connections between saidpawl and crankpin, means operated at the limit of each reciprocationbetween work and wheel for oscillating said crank-pin about its axiswhereby said pawl is drawn to its limit as the crankpin passes thedead-center, thus rotating the ratchet-wheel.

39. Agrinding-machine having a'reciproeating' table for supporting thework, a grinding-wheel having a movable support, means for advancingsaid wheel toward the work upon each reciprocation of the tablecomprising a ratchet-wheel, connections between said ratchet-wheel andthe grinding-wheel support which are adapted to move said support whensaid wheel is rotated, a suitably-guided reciprocating pawl, acrank-pin, connections between said pawl and crank-pin, means operatedby said table as it reaches the limits of its travel, for oscillatingsaid crank-pin about its axis, and Vmeans for varying the amplitude ofits oscillations, whereby said pawl is drawn back to its fixed limit asthe crank-pin passes the dead center rotating the ratchet wheel andadvances to its variable limit as the crankpin passes the dead-centerand finishes its oscillation. I v

40. A grinding-machine having a reciprocating table for supporting thework, a grinding-wheel having a movable support, means for advancingsaid wheel toward the work upon 'each reciprocation of the table,comprising a ratchet-wheel, connections betweensai'd IOO IIO

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